binormal

American  

[bahy-nawr-muhl, bahy-nawr-] / ˈbaɪˌnɔr məl, baɪˈnɔr- /

noun

Geometry.

1. the normal to a curve, lying perpendicular to the osculating plane at a given point on the curve.

---

Etymology

Origin of binormal

First recorded in 1840–50; bi- ¹ + normal

Example Sentences

The Frenet frame of reference is formed by the unit tangent vector, the principal unit normal vector, and the binormal vector.

From Textbooks • Mar. 30, 2016

When studying motion in three dimensions, two other vectors are useful in describing the motion of a particle along a path in space: the principal unit normal vector and the binormal vector.

From Textbooks • Mar. 30, 2016

Note that, by definition, the binormal vector is orthogonal to both the unit tangent vector and the normal vector.

From Textbooks • Mar. 30, 2016

At every point P on a three- dimensional curve, the unit tangent, unit normal, and binormal vectors form a three- dimensional frame of reference.

From Textbooks • Mar. 30, 2016

A tangent, principal normal, and binormal are a convenient set of rectangular axes to use as those of reference, when the nature of a curve near a point on it is to be discussed.

From Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 6 "Geodesy" to "Geometry" by Various